Referring to FIG. 1, a hot water heater assembly 10 generally includes a tank 12 including a heating element (not shown), a cold water inlet pipe 14 and a hot water outlet pipe 16. As the hot water is turned on, for example the hot water spigot in a household, hot water exits through the hot water outlet pipe 16 while cold water flows through the cold water inlet 14 into the tank 12. The amount of hot water leaving the tank equals the amount of cold water replaced and heated in the tank.
Considerable heat is lost through the water inlet and outlet piping of a water heater. The heat loss is due primarily to thermal circulation and not as a result of conduction through the piping itself.
FIG. 2 displays a prior art attempt to control the heat lost through the water inlet and the water outlet piping of the water heater. A prior art cold water inlet heat trap assembly 20 includes a nipple 22, a seat 24, a cage 26, and a ball 28. The nipple 22 is received in the inlet 30 of the tank 12 and also received in the outlet 32 of the cold water inlet pipe 14. The nipple provides the housing for the heat trap assembly 20. The seat 24 is formed inside the nipple. The seat includes an opening having a diameter smaller than the diameter of the ball 28. The cage 26 is a cage-like structure that traps the ball inside the nipple as water from the inlet pipe 14 flows through the nipple 22 into the tank 12. The ball 28 has a specific gravity less than 1.0 so that when no water is flowing through the cold water inlet pipe and the nipple into the tank the ball floats up to cover the opening at the seat.
In use, the hot water is turned on somewhere in the household, or wherever the tank is located. Almost simultaneously, hot water exits the hot water tank 12 through the hot water outlet pipe 16 and cold water enters the tank 12 through cold water inlet pipe 14. As cold water flows through the nipple 22, the water dislodges the ball 28 from the seat 24 and the ball moves toward the cage 26. The cage 26 catches the ball and retains the ball inside the nipple. The cage has openings to allow the water to flow around the ball and enter the tank 12. When the hot water is turned off, the ball 28 floats upwardly back towards and into engagement with the seat 24 trapping heat below it.
A similar hot water heat trap assembly 40 is provided on the hot water outlet pipe 16. The heat trap assembly 40 includes a nipple 42, a seat 44, a cage 46, and a ball 48. The nipple 42 is received in the inlet 50 of the hot water outlet pipe 16 and in the outlet 52 of the tank 12. The seat 44 and the cage 46 are of the same or similar construction of the seat 24 and the cage 26 of the cold water heat trap assembly 20. In the hot water heat trap assembly 40, the seat 44 and the cage 46 are disposed on opposite ends of the heat trap assembly as compared to the cold water heat trap assembly 20. The ball 48 of the hot water heat trap assembly 40 has a specific gravity greater than 1.0. Accordingly, when the hot water exits the tank 12 into the nipple 42, the ball 48 is dislodged from the seat 44 and retained by the cage 46. The cage has openings to allow water to pass around the ball and through the nipple. When the hot water is turned off in the household, no hot water is flowing through the nipple 42 and the hot water outlet pipe 16 so that the ball 48 sinks toward and into engagement with the seat 44 trapping heat below.
A problem with the above-mentioned energy saving device involves “chatter” of the balls 28 and 48 inside the nipples 22 and 42. Because the diameter of the nipple required to allow the ball to float freely inside the nipple and the influence of water flowing through the nipple, the balls tend to rotate at a relatively high speed. The high speed rotation of the balls allows the ball to contact the nipple and “chatter” making an audible sound that is noticeable to those standing near the water heater. To some consumers, this is considered objectionable, although it does not represent a defect in the heat trap. Accordingly, it is desirable to provide a heat trap assembly that provides the same or better energy efficiency of the prior art heat traps while also eliminating the “chatter” that accompanies such heat trap assemblies.